are there different kinds of b12 injections at Olympia B12 Shots vs. IV Infusions:

"Arava (leflunomide) dosing, indications, interactions, adverse effects, and more"

Principally, this is due to the fact that individuals who are highly B vitamin deficient may experience a delay in the conversion of Cyanocobalamin into Methylcobalamin

I found an agency willing to sponsor me Major Model Management which allowed me to apply for an O-1 visa, reserved for individuals who can demonstrate extraordinary ability at the top of their field

Due to the complicating factor of a shot and the extra cost, it seems the best route for most people is to focus on getting adequate B vitamins from food, and supplement as necessary.